mtd: introduce mtd_unlock interface

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 870f2cb..fe09cd2 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -838,7 +838,7 @@
 		if (!mtd->unlock)
 			ret = -EOPNOTSUPP;
 		else
-			ret = mtd->unlock(mtd, einfo.start, einfo.length);
+			ret = mtd_unlock(mtd, einfo.start, einfo.length);
 		break;
 	}
 
diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index 97d6360..272ebc0 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -596,7 +596,7 @@
 			size = len;
 
 		if (subdev->unlock) {
-			err = subdev->unlock(subdev, ofs, size);
+			err = mtd_unlock(subdev, ofs, size);
 			if (err)
 				break;
 		} else
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index e36191a..4a21557 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -340,7 +340,7 @@
 	/* Some chips always power up locked. Unlock them now */
 	if ((mtd->flags & MTD_WRITEABLE)
 	    && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
-		if (mtd->unlock(mtd, 0, mtd->size))
+		if (mtd_unlock(mtd, 0, mtd->size))
 			printk(KERN_WARNING
 			       "%s: unlock failed, writes may not work\n",
 			       mtd->name);
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index a5e7a21..d65af37 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -287,7 +287,7 @@
 	struct mtd_part *part = PART(mtd);
 	if ((len + ofs) > mtd->size)
 		return -EINVAL;
-	return part->master->unlock(part->master, ofs + part->offset, len);
+	return mtd_unlock(part->master, ofs + part->offset, len);
 }
 
 static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)